package com.atguigu.gulimall.product.service.impl;

import com.atguigu.gulimall.product.service.CategoryBrandRelationService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.stream.Collectors;

import com.baomidou.mybatisplus.core.conditions.query.QueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.atguigu.common.utils.PageUtils;
import com.atguigu.common.utils.Query;

import com.atguigu.gulimall.product.dao.CategoryDao;
import com.atguigu.gulimall.product.entity.CategoryEntity;
import com.atguigu.gulimall.product.service.CategoryService;
import org.springframework.transaction.annotation.Transactional;


@Service("categoryService")
public class CategoryServiceImpl extends ServiceImpl<CategoryDao, CategoryEntity> implements CategoryService {

    @Autowired
    CategoryBrandRelationService categoryBrandRelationService;

    @Override
    public PageUtils queryPage(Map<String, Object> params) {
        IPage<CategoryEntity> page = this.page(
                new Query<CategoryEntity>().getPage(params),
                new QueryWrapper<CategoryEntity>()
        );

        return new PageUtils(page);
    }

    @Override
    public List<CategoryEntity> listWithTree() {

        //1.查出所有分类    没有查询条件,所以填null
        List<CategoryEntity> entities = baseMapper.selectList(null);

        //2.组装成父子结构
        //2.1)找出所有的一级分类
        /**
         * .stream()为集合创建串行流
         * .filter过滤
         * ()->{}箭头函数,如果()里面只有一个参数,则()可以省略,如果{}里面只有一条语句,则{}可以省略
         * 这里要过滤的是每一个元素,即categoryEntity
         * collect(Collectors.toList)转换成list集合
         */
        List<CategoryEntity> level1Menus = entities.stream().filter((categoryEntity) -> {
            return categoryEntity.getParentCid() == 0;
        }).map((menu)->{
            menu.setChildren(getChildrens(menu, entities));
            return menu;
        }).sorted((menu1,menu2)->{
            return menu1.getSort() - menu2.getSort();
        }).collect(Collectors.toList());
        return level1Menus;

    }

    @Override
    public void removeMenuByIds(List<Long> asList) {
        //TODO 1.检查当前删除的菜单,是否被别的地方引用

        //我们更多用的是逻辑删除,就是在数据库里面有一个字段是标志位,为0是删除!而baseMapper.deleteBatchIds()则是物理删除,直接在数据库就删除了!
        baseMapper.deleteBatchIds(asList);
    }

    @Override
    public Long[] findCatelogPath(Long catelogId) {
        List<Long> paths = new ArrayList<>();

        List<Long> parentPath = findParentPath(catelogId, paths);
        System.out.println("开始前  " + parentPath );//[225,34,2]
        Collections.reverse(parentPath);//[2,34,225]
        System.out.println("开始后  " + parentPath );//[2,34,225]
        System.out.println("这个是什么?" + parentPath.toArray());//这个是什么?[Ljava.lang.Object;@78d73b1b
        System.out.println("那这个是什么?" + parentPath.size());//那这个是什么?3
        return parentPath.toArray(new Long[parentPath.size()]);
    }

    /**
     * 级联更新所有关联的数据
     * @param category
     */
    @Transactional
    @Override
    public void updateCascade(CategoryEntity category) {
        this.updateById(category);
        categoryBrandRelationService.updateCategory(category.getCatId(),category.getName());
    }

    //[225,34,2]
    private List<Long> findParentPath(Long catelogId, List<Long> paths){
        // 1.收集当前节点id
        paths.add(catelogId);
        CategoryEntity byId = this.getById(catelogId);
        //System.out.println("byId:  " + byId);
        if (byId.getParentCid()!=0){
            findParentPath(byId.getParentCid(), paths);
        }
        return paths;
    }

    //通过递归查找所有菜单的子菜单                 当前菜单            从哪里获取子菜单,这里是所有菜单
    private List<CategoryEntity> getChildrens(CategoryEntity root, List<CategoryEntity> all){

        List<CategoryEntity> children = all.stream().filter(categoryEntity -> {
            return categoryEntity.getParentCid().equals(root.getCatId());
        }).map(categoryEntity -> {
            //2.找到子菜单
            categoryEntity.setChildren(getChildrens(categoryEntity, all));
            return categoryEntity;
        }).sorted((menu1,menu2)->{
            //2.菜单的排序
            return (menu1.getSort()==null?0:menu1.getSort())-(menu2.getSort()==null?0:menu2.getSort());
        }).collect(Collectors.toList());
        return children;
    }
}